Many critical circuits such as band gap references and bias current generators use feedback schemes to regulate at a specified non-zero equilibrium point. However, most, if not all, of these circuits possess an alternate undesirable equilibrium. Under some conditions these circuits do not start but remain in their original zero state. Start-up schemes provide a suitable perturbation that causes these systems to leave the zero state and approach the desired operation point. Typically, large resistors provide a passive dc path into a key node that pulls the circuit away from the zero state. Such a start-up resistor is typically at least 10 mega-Ohms. Some problems typically caused by using start-up resistors are that they occupy large areas of the layout, they usually consume power, and they may perturb the nominal bias point after start-up. Additionally, component variation in the start-up resistor may cause a certain percentage of these circuits not to start.